Best way to create a simple and economic steam machine for steaming wood?

Question

I want to build a simple steam machine for steaming wood to bend.

To do this I must place the wood into a sealed PVC pipe and pump steam into it. The PVC pipe part is the easiest part. Producing steam in a simple and economic way is where I need help.

I was thinking of simply using the element from an electric kettle, but these use quite a lot of electricity - the wood must be steamed for at least an hour. I also looked at a clothing steamer, but these seem too weak.

'Pumping' the steam into the PVC pipe is not a problem, as long as the pipe is higher than the steam source, so there is no need for forced induction.

Has anyone built something like this before?

Would anyone know a way of building a simple and cheap steam making machine?

Answer 1

The container doesn't have to be a PVC pipe. Wood boxes were the traditional solution, and still seem to be more common among woodworkers than the PVC approach.

There are steam generators available from woodworking stores which are a bit more effective than an electric kettle. They may or may not be significantly more energy-efficient; boiling water takes the same amount of energy no matter how you do it, so the only question is how much energy gets lost to the environment rather than going into the water and being kept in the steam.

Answer 2

I have made and used one of these. I used a section of downspout for gutter systems. The parts I was bending were less than an inch in diameter. The chamber was in 2 pieces, 1 pc 3' the other 7' the crimped ends that downspouts have as the slip joint for separation. The ends were cut and folded to seal the ends and pop riveted to hold, no sealant used. The end was drilled to accept the largest flexible hose adapter I could find, my case was an 1 1/4" radiator hose. The tricky part was the tanks and heat source. There must be enough heat generated to create a LOT of steam. I used a charcoal grill. If I had a propane burner like the type used for steaming crabs outdoors would have been perfect. Those are used here in Maryland USA, elsewhere I'm sure too. The trickiest part is the large tank needed. I just so happened to have an ancient rusty 5 gallon gas tank for an outboard motor for a boat. I tapped the pipe into the tank, which electrical metal conduit connectors did well, accessing through the fill hole to set the nut on the inside. I probably could have set the pipe tap directly in the top as easily. It needs top hold enough water to steam for say maybe a half hour, not sure anymore, but there is a lot of water needed and a lot of heat to boil it.

Answer 3

I have been thinking about building a steam box. I figured I would pick up a couple stainless TIG welding electrodes at the local welding shop and bend them into a serpentine shape with about a half inch gap between them that would fit in the bottom of a 5 gallon paint bucket. Make some spacers out of plexiglass so the two electrodes are spaced away from each other and held up off of the bottom of the bucket. Connect each electrode to one side of an old line cord. Fill the bucket with enough water to cover the electrodes by an inch or so, snap the top on (use the spout for getting the steam out of), and plug the thing in. Adding a bit of salt or baking soda may make it boil up a bit faster. Just don't touch the water while it is running.